Ice cream freezer



Oct. 25, 1938. H.. F. swENsoN ICE CREAM FREEZER Filed Jan. 22, 195egmc/nto@ HqrvcgyESwewop Patented Oct. 25, 1938 UNITED STATES ICE f y f10E CREAM Finalizan Harvey F. Swenson,` Seattle, Wash. ApplicationJanuary 22, 1936.kk $0,213 3 claims.- (ci. 1259-9) My invention relatesto ice cream freezers .and particularly to an ice crealm freezer that isadapted for use in ice cream parlors, hotels, drug stores andrestaurants where the ice cream [is 7,5 servedl to the trade directlyfrom the freezer.

Certain mechanical objects of the invention are first, to provide an icecream machine having a freezer drum equipped with a plurality of ns orsplines whereby the area of the freezing: trans- .119 fer surface isconsiderably increased, and av uniform passage is provided for the flowof the refrigerant whereby settling and collection of 1ubricant on metalsurfaces in the refrigeration system is eliminated; second, to provide afoot l pedal for electrical operation and control .of the freezerwhereby ice cream may be discharged directly from the freezer drum intoreceptacles thus leaving both hands free to handle thereceptacles;third, to provide .a cut-off door for V240 the discharge port of thedrum which doorr is designed and shaped in such manner that both largeand small receptacles may be equally and readily lled therefrom; fourth,to provide afsimplified front bearing for the dasher which is trouble 2.5 free, simplifies the opening and closing `of the drum door, andeliminates expensive replacement cost; and fifth, to provide aleak-proof gasket consisting of a small rubber tube set into an 4annulargroove on the inside of the drum door whch :.30 is easy to remove, cleanor replace.

:35 operate without accompanying operation, of the freezer motor whichoperates the dasher ofthe freezer unit.

In the drawing: Figure 1 is a View in front elevation of the com- 450plete machine; Fig. 2 is a view in vertical section taken substantiallyon a broken line.2-.2f0fVF .g. 1 and showing certain parts in elevation;Fig. :3 is an enlarged fragmentary View in vvertical sec- E*55rangement.

YReferring.in deijail A to Ltljie Adrawing throughoutwhichliklerevference *designate like parts', .the nu'- meral 5indicatesthe main frame` of the machine which may have a housing l6superimposed thereon`ir1 l`anydesirablei manner. i A freezer tI .5 ismountedl within thehousig inany suitable' manner, and yal'refrigler'atking f8 e envelopes saidfreezer drum vleaving anexpansionvchamber 'therebetween A l sheetfmetal casing 9v surrounds.the.rfligeratingfdrum and the space between is 11 ,0 'lled'-with 'corkor other insulative" IriaterialV as shown at, l 0.' The forward-ends"of` the casing'and refrigerating ldrum are @closed-byva front lwall,llll leavingfthe' forward end of the. freezer 'drum' open as most-vclearly shown inligj, 3 ofV thed'rawing. 15

A drum idoorflzis' hinged atlete thejfront wail Il. Av barili is alsoconnected to the hinge I3..and extends`directly-`across'the' outsideofthe door with its forked end |5`r arranged tostr'addle abolt .i6 which'is pivot'ally connected to Lthe 20 Lfront wall `ll and Iiayflie 'swung'outwardly fas yshown'i'ny dottedlines'in Fig. 1. Saidbolt isfpr'osameislscreweclv down tightly against the `forked .end -I .5,the.b,arI4`will hold the door I2 in a closed 2.5VV

leaky-proof position; An importantfeature of the invention 1j esides'in.the` small rubber 'tub'e gasket Vided'in the 'rear surface efthedoor|21 `Thus,

when .the door is held lm thelcised A.psition' by 30 The upperportiondof. the drum door I2 is pro- 35 .vided :with ka 'downspout entryportj Z0 which communicates directly:'withfthe interior ,of the freezerdrum`1 Whenftle door i's closed'. The lingredients4 for makingficecream` areiedw into the `.drum through'thisentry port and its top ispro- ,40

kvidedlw'ith a `hingedlid 2l which *excludesdust and other foreignmatter.r The'lower Afportion'of "the door l2 jis}provided wth' aprojecting distion of the forward part of the freezer drum andchart-,felv port .22] fwhlich alsoy communicates' with thefreezer drumIwhen itsjdoor is closed. [Af cut- 4 5 toffe door .23 is "pivoted tothis port by v`a boli-,.24

whichfhas a heavy spring 275 interposed between the hea'd'of the boltandthe door for compressing the Vcut-,off door 'against the open end lofthev port 'thusmaking it leak-proof. `This door is v50 pivotally raisedby a` handle 26;' and lan important'` feature xof thisdoor residesin`the sonrievvhat'reef y ltangular recess"21 provided in its loweredgeportion. This `rectangular recess, withits rounded"cornersglisyso'shaped -that it lwill vpermit a smalli55 n' quantity aswell as a large quantity of ice cream to be discharged from the port 22,depending upon the distance the door is raised, and thus large as wellas small receptacles may be filled with equal facility. When fillingreceptacles, they are either held in the hands or placed upon the shelf28 which is secured to the frame 5 or housing 6.

Another important feature resides in the small front bearing A29, shownin detail in Fig. 6, which has a flanged head 30 and a hollow recess 3|.This bearing fits into a hole 32 through the drum door l2, between theentry and discharge portsl 2| and 22 respectively, and. iscentrallydisposed with respect to the freezer drum VItsA head 3D bearsagainst the outside of the door and is engaged by the bar I4 which thusAserves the double purpose of retaining both the d''or andthe bearing ina closed leak-proof position as willbe Aunderstood. The recess 3| inthisbearing receives the reduced end of the'dasher shaft' 33 `which V'freelyrotatesl therein;j This small front bearing issimple and inexpensive toinstall andrenew, and provides novel means whereby the freezer drum door|2` may be opened and closed without expensive and complicatedstructure.

The finsior splines 34, which are interposed in the expansion chamberbetween the freezer and refrigerator 'drums 1 and 8 respectively, formstill another important feature of the invention.

These fins are rectangular in cross section and are preferably, thoughnot necessarily, an integral part of the refrigerator drum`8. Theyex-`tend longitudinally of the drums, each alternate one terminatingshortof the rear end of the drum 'and withthe other intermediate onesterminating short of the frontend of the drum, as shown at '35, so as toform a continuous and circuitous p assage back and forth allaround thedrum'. Thus, the refrigerant, whichl Venters the expansion chamber underpressure inthe form of liquid through a small pipe 36dividesitse1f,.h'alf flowying around one sideofthedrurn' and half going aroundthe other side, and passesjoutthrough a larger Ypipe 3l. uniform passagefor-the flow -ofthe refrigerant 'around the drum whereby lubricatingoil,v which is v carried insuspension bythe refrigerant, is ,1.vpreventedjirorrfA settling and collecting von, the

These splines or fins provide a metal surfaces in the` refrigeratingsystem, and materially increase the area ofthe freezing transfersurface, and `thus increase the efficiency of the Y machine.

The rear end of thedasher shaft 33 is enlarged by a flange head 38whichis' Vcentrally provided with a recess and groove or slotv39'diametrically across the rear end ofthe head which `recess receivesthe inner end of arstub shaft 40, and a pin f4| passing therethroughandiseated in the groove forms a detachable connection'for the rear 'endof the dasher as'shown in Fig.V 7. Thestub shaft 40 isfjournaled throughthe rear end of the freezing and refrigerating drums, and "its outer endis providedY with a large pulley 42 having belts 43 extending to a smallpulley 44 keyed to the shaft of a dasher motorv 45. The dasher shaftv 33has a 'pair of oppositely curved blades 46 secured to or integral witheach of its ends'which blades rotate finjuxtaposition with the innerwall of the freezer 'drum"|, and aplurality of oppositely disposed iiat"spacedapartpaddlesor ngers 4T'integrally connected to the dasher shaft,terminate inside or 'short of the dasher blades; "j i The'paddles orfingers 41j' aresofslanted as to causethe semi-'frozen ice cream' tomove forward toward the discharge port 22 when the dasher is rotated,say, in a clockwise direction. A foot pedal 48 is fulcrumed to the lowerportion of the frame 5, and a rod 49, which is pivotally connected tosaid foot pedal, extends upwardly to av foot pedal switch 50.k Pressureof the foot upon said pedal causes the switch to rise and close thecircuit from lead-in wires and 52 to the dasher are for momentary useand as a convenience in .filling and serving ice cream receptacles.

They `are of prime importance for the reason that an Yattendant may ll ahalf dozen receptacles, such as saucers or cones carried in both hands,by stepping on the foot pedal thus causing the dasher to force the ice'cream within the freezer drum I into the discharge port 22, and byraising andY lowering the cutfoff door 23 with the wrist or otherdisengaged part of the hands or arms. The foot pedal results in quickerservice, the use ofless electrical power, and in a better quality of icecream.

A refrigerating unit, comprising a compressor 54,`a"motor 55 foroperating the compressor, a pressure tank 56, and a pressure controlswitch 51, is mounted on the lower part of the frame 5. It is understoodthat no claim of novelty is made for the compressor except insofar as itmay en ter into novelcombination with the elements of the ice creamfreezer. The small pipe 36 conveys the compressed refrigerant from thepressure tank 56 tothe expansion chamber between thefreezer andrefrigerator drums 'l and 8 respectively wherein the refrigerantexpands, creating the necessary frigidity, and then returns through thelarger pipe 31 to the compressor 54 and tank 56 vthus completing itscycle. I prefer to use methyl Vchloride as the refrigerant by reasonofits nonmaintained by the compressor depending upon conditions ofoperation, and the pressure switch 51'is`conn'ected to the compressorand interposed in the circuit for reasons presently set forth. Athermostatic expansion valve 58 is interposed in the small high pressurepipe 36, and theV entire portion of the pipe between said expansionvalve 'andthe compressor tank 5S, being normally at a partialk vacuum orunder low pressure, the pres- Ysure within said pipe portion willincreasev upon operation of the compressor and extend into the expansionchamber between the drums 'l and 8 where it will rapidly expand thusabsorbing high temperature and creating low temperature which freezesthe ice cream mix within the freezer drum .1." A magnetic valve switchv59 is also interposed in thehigh pressure pipe 36 for reasons presentlyset forth.

, A thermal bulb 60 is connected to the low presure'return pipe 31 and acapillary tube connects said bulb with the thermostatic expansion valve58, which valve is'so adjusted that, when frost is thetemperature oramount of frost ron-the low 'pressure return pipe.H The'frost line doesnot reach the thermal bulb until the latterstagesof freezing takes placewhen Vthere isV less expansion ofV the refrigerant and a consequentoverflow` of caused to operate and shut off the expansion Valve 55, thusenabling the compressor1 54 to function more rapidly and increasing thespeed of the freezing process.

In the operation of the system, assuming that ice cream mix at atemperature of from forty to seventy degrees Fahrenheit is placed in thefreezer drum 1, the freezer hand switch designated by the numeral 6| ismanually closed whereby the circuit wire 62 is also closed. The currentwill ow through the magnetic valve 59, opening same and allowing liquidhigh pressure refrigerant to pass into the thermostatic expansion valve58 which allows a measured amount to pass on into the expansion chamberbetween the drums 1 and 8. It being understood that the double polecompressor hand switch 63 is closed at all times, and inasmuch as thepressure switch 51 is connected to the magnetic valve 59, by wires 64and 65, and said pressure switch being set to close at a pressure ofsubstantially ve pounds, this switch will close and allow the current toflow through a wire 66, through the foot pedal switch 50 in its normallylowered position, through the wire 5l and a thermal coil operated dashermotor switch 61, to the dasher motor` 45, operating same and completingits circuit by returning over the wire V52.

At the same time the current will also ow through a shunt wire 68,through the double pole hand switch 63, then through a Wire 69 to thecompressor motor 55, operating same and returning through a wire 10,through the other pole of the compressor hand switch 63 and thuscompleting its circuit through the wire 52. The thermal switch 61 isprovided in case the dasher becomes stalled by over frozen cream orother cause which would build up an overload of current, this switchwill throw out thus breaking the circuit and preventing the dasher motorfrom being burnt out. Provision is also made for operating this thermalswitch by hand in cases of emergency. v

When the ice cream mix is frozen to the proper consistency, the freezerhand switch 6l is opened which closes the magnetic valve 59 and thusshuts off all ow of the refrigerant. This will cause a partial vacuum tobe built up in the compressor 54 by suction thus reducing thecompression which causes the pressure switch 51 to open. This pressureswitch, being wired in circuit with both the dasher motor 45 andcompressor motor 55, both of said motors will be stopped. Herein liesthe most important electrical feature of the invention, namely, thecompressor motor 55 cannot operate without'running the dasher motor 45for the reason that the current which operates the compressor motor mustiiow through part of the same circuit which operates the dasher motor,namely through the wire 56, it being understood that the foot pedalswitch 50 is in its normally lowered position. For, if we assume thatthe freezer hand switch 6l is open and the compressor hand switch 63 isclosed, it is apparent from the foregoing that the said open hand switchwill close the magnetic valve 59 thus reducing pressure of thecompressor 54 and thereby causing the pressure switch 51 to open and thewire 66 to be thrown out of circuit. This willfprevent current frompassing over the wirep68 through the compressor hand switch 63'and tothecompressor motor 55 over. the Wire 69, vthus stopping said compressormotor. u This featureis important Afor the reason that it'preventstheice cream mixture within the freezer: drumal .from being frozen solidwhile l in a static conditioncaused by non-operation of the dasher aswill be understood.

'Ihe dasher motor 45 may beV operated by the foot 'pedal switch 50without closing the Acompressor hand switch 63, and the circuitissoarranged that the dasher motor may be operated by the foot pedal switchindependently of the pressure switch 51 or any of the other controls onthe machine except the thermal switch 61. In the operation of the footpedal switch, the

current flows through same in its normally lowered position only whenthe pressure switch 51 is closed, and in this position the dasher motorcannot be operated by said foot pedal switch. However, when pressure isapplied tothe foot pedal and said foot pedal switch is raised tocomplete the circuit through the wire 5I, which is connected directly tothe outside source of power and is alive at all times, the dasher motorwill be set in motion. Inasmuch as the compressor motor is wired inahead of the foot pedal switch at the point designated by the numeral1I, the operation of the foot pedal switch does not effect the operationof the compressor motor. This independent feature of operating thedasher motor is particularly useful in serving iceA drum having anopenend, a front wall surrounding the open end, a doorr hinged to thefront wall and arranged to bear against the front wall and close theopen ydrum end, an outwardly project-- ing discharge port carried by thedoor and communicating with the drum, Va cut-off door pivoted flatly tothe outer end of the port and arranged Yto open and close the port whenit is pivotally swung up and down, and said cut-off door having arectangular recess in its lower edge portion `ranged to be brought intocommunication with the port when the door is pivotally moved to regulatethe size of the port opening.

2. In an ice cream freezer comprising a freezer drum having an openfront end, a front `wall surrounding the opening, a door hinged to thewall and arranged to close the front end of the drum, said door having ahole therethrough concentric with the drum, a dasher mounted forrotation within the drum and having a central shaft with a reducedprojecting end arranged to register with the hole through the door, asmall bearing having a recess and a flange head. inserted into the holewith its head bearing against the exterior of the door, the recess inthe bearing arranged to receive the reduced -end of the dasher shaft, across bar hinged to the front wall and arranged to `engage the flangehead of the small. 'Y y bearing, and means. for clamping said baragainst the head of said bearing. l

3. In an ice cream freezer comprising a freezer drum having an openfront end, a front wall surrounding the open end, a door hinged tc' thewall and arranged .to close the front end vvof the drum when the door isswung into engagement with the front wall, said door having a holetherethrough concentric with the drum, a dasher mounted for rotationwithin the drum` and having a central shaft with a reduced projectingend arranged to register with the'hole through the' door, a smallbearing inserted in `the -ho1e in the door, sadrbearng havhga 'recessand aflangev head bearing against the-exterior of the door, the reduced.end of the dasher shaft mounted in the recess of the'bearng, acrossbarrhnged to the front wall andrextendng acrossvthe doorin en- HARVEY F.sWENsoN.

